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Re: Harlequin 1.2 still available?
In article <slrn8k8fme.k9p.neelk@brick.cswv.com>, neelk@alum.mit.edu
wrote:
> Rainer Joswig <rainer.joswig@ision.net> wrote:
> > MCL's speed made a big improvement with the introduction of the G3.
> > It runs ten times faster on a 292 Mhz G3 compared to a 100 Mhz
> > PowerPC 603e. The PowerPC version of the Apple Dylan IDE runs *very*
> > fast on today's Macs.
>
> Why is this? Is it because of general RISC-has-easier-code-generation
> reasons, or is there some additional hardware support in PowerPC for
> dynamic-language features. (IIRC, the Sun SPARC has hardware support
> for tagged integer arithmetic.)
Neither. The PPC750 ("G3") is just that much better at running almost
anything than the PPC603e was, in the same way that the
PentiumPro/II/III/Celeron is that much better than the Pentium.
The 603e had only 16 KB I-cache + 16 KB D-cache, each 4-way associative.
The PPC 750 has 32 KB I-cache + 32 KB D-cache, each 8-way associative.
Even more, PPC750 machines usually have 512 KB or 1 MB of L2 cache
running at 1/2 or 2/3 the processor speed (150 - 200 MHz), while the
machines with the 603e in them were low end machines (the high end
machines of the time had 604's) which had either no L2 cache at all, or
else no more than 256 KB which ran at the motherboard speed (40 - 50
MHz). The PPC750 also has limited out-of-order capability and much
better branch prediction than the 603e.
I recently bought an old "PowerCurve" Mac clone with a 120 MHz PPC601
and no L2 cache and upgraded it with a US$189 PPC750 processor card
running at 250 MHz with 512 KB of L2 cache running at 125 MHz. Certain
things such as adding titles to a QuickTime movie using Adobe Premier
became *FORTY* times faster with the PPC750 CPU than with the PPC601, on
the same motherboard (running at 40 - 45 MHz), same RAM, same disks.
-- Bruce
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